Curved screens and method of making same



l J. HOURDIAUX May 21, 1968 CURVED SCREENS AND METHOD OF MAKING SAME 2 Sheets-Sheet 1 Filed June 28, 1965 Ihvem ok Jul. HDURDIAUX 3,: m1, MC

ATToR N575 May 21, 1968 l J. HOURDIAUX CURVED SCREENS AND METHOD OF MAKING SAME 2 Sheets-Sheet Filed June 2'3, 1965 FIG. 3

INVENTOR JULES HOURDIAUX ATTORNEYS United States Patent 3,384,432 CURVED SCREENS AND METHOD 0F MAKING SAME Jules Hourdiaux, 96 Ave. de Versailles, Paris 16eme, Hauts-de-Seine, France Filed June 28, 1965, Ser. No. 467,289 Claims priority, application France, June 30, 1964,

980, 25 5 Claims. (Cl. 350-125) ABSTRACT OF THE DISCLOSURE The present invention has essentially for its object improvements in curved screens for projecting motion-picture films or other images.

In the US. Patent No. 3,295,910, issued Jan. 3, 1967, in the name of the applicant and entitled Curve-cl Projection Screens, a projection screen is contemplated which comprises a series of individual panels secured together in side-by-side relation. Each panel comprises a plurality of juxtaposed screen elements overlapping partially each other and having each a light-diffusing front face, said front faces together constituting a single curved projection surface and being parallel to a direction perpendicular to the projection axis.

The diffusing elements forming said known curved screens may consist of rods having a T, L, trough, crescent or other cross-sectional contour, and comprising a convex face preferably so treated as to produce an integral reflection of the light received from the projector, this face constituting the projection face.

These rods have a length equal to the panel height and are clamped at the upper and lower portions of the panel by fastening and pivot means whereby the rods may be given the desired orientation.

This specific form of embodiment of the panels may be used to advantage for constructing projection screens of relatively moderate height, that is, inferior to twentythree feet.

When on the other hand, it is contemplated to erect screens of relatively large dimensions, that is, of a height equal to or greater than twenty-three feet, it is obvious that the use of rods of very great length is attended by serious difficulties as far as the transport and mounting operations are concerned. Moreover, these very long rods are liable in most instances to distortion effects preventing the setting of each elementary screen at the desired angular position throughout its height.

It is the object of the present invention to avoid these inconveniences and this invention .is characterized in that each diffusing element extending throughout the height of a panel consists of a plurality of rods disposed end to end and assembled at their adjacent ends by means of connecting members.

Thus, panels may be constructed from relatively short rod elements which are therefore easy to transport and handle.

According to another feature of this invention, each aforesaid connecting member may consist of a rigid 3,384,432 Patented May 21, 1968 sheath or like member of substantially cylindrical crosssectional contour which has formed on its concave face slideways or the like in which the ends of the two rods to be connected are adapted to be fitted.

This sheath constitutes a fastening means which is both simple and convenient and permits a rapid mounting of the rods.

According to another feature of this invention, said connecting member may consist of a clamp or like member made from a resilient material and comprising a rear face of substantially cylindrical configuration, adapted to bear on the concave faces of the rods to be interconnected, and a front face adapted to bear on that portion of the front face of the rods which is covered by the ladj acent rods.

Other features of the invention will appear as the following description proceeds.

In the attached drawing given by way of example only:

FIGURE 1 shows two superposed rods assembled by means of a sheath-like connecting member, according to a typical form of embodiment of this invention;

FIGURE 2 is a section taken upon the line 11-11 of the sheath shown in FIGURE 1;

FIGURE 3 is a perspective diagrammatic view showing superposed rods forming a screen element and mounted on a panel forming a part of the projection screen;

FIGURE 4 shows a clamp-shaped connecting member;

FIGURE 5 is a fragmentary section taken upon the line VV of a screen portion shown in FIGURE 5, said screen being provided with said clamp-shaped connecting members;

FIGURE 6 is a front view showing one portion of a screen provided with clamps of said type;

FIGURE 7 shows the cross-section of one portion of a screen made of rods according to this invention.

FIGURES 1 and 2 illustrate a typical form of embodiment of a connecting member 1 contemplated for assembling the elementary screens consisting of rods 4 and 5 having a trough-shaped cross-sectional contour, the convex faces 4a and 5a of said rods receiving and diffusing the light emitted by the projector (not shown). This member consists of a sheath or the like having a substantially part-cylindrical configuration and, on its concave face 1a, a pair of dovetail-sectioned in-turned shoulders 2, 3 between which the ends of rods 4, 5 are adapted to be fitted. Each rod engages the sheath so as to occupy about one-half of its height as shown in FIGURE 1, the two rods thus engaged contacting each other with their adjacent ends.

Thus the two rods 4 and 5 have their end portions fitted between the dovetail-shaped shoulders 2, 3 of the sheath 1 and are rigidly held and assembled by this member.

Preferably, the sheath and notably its concave face It: is given substantially the same radius of curvature as the rods 4 and 5. It is to he noted that the convex face 1b of sheath 1 which covers the abutting ends of rods 4 and 5 constitutes a part of the projection surface of the screen as do the front convex faces 4a and 5a of rods 4 and 5.

FIGURE 3 shows the two superposed rods 4 and 5 of FIGURE 1, and the connecting member I mounted on a panel 10 of the type described in the aforesaid US. patent. Of course, a plurality of screen elements each consisting of two rods assembled by a sheath, are mounted on said panel, the juxtaposed screen elements in the juxtaposed panels together constituting the single curved projection surface.

The sheath 1 may be made from any suitable and sufliciently rigid material, for example metal. Preferably, the

.30 same material as that constituting the rods 4 and is used so that no difference in aspect may appear between this sheath and the rods when the treatment necessary for imparting a light-diffusing characteristic to the screen surface is applied. As a result, the sheath 1 is practically invisible to the audience in the theatre.

According to a specific form of embodiment illustrated in FIGURES 4, 5 and 6 the connecting member is made from elastic material and in the form of a clamp 6. This member has a p-art-cylindrical face 6a of a width substantially equal to the width of the rods to be assembled and a substantially narrower face 6b. This clamp is made from a material having a sufficient resilience, for example steel, to permit the elastic movement of faces 6a and 6b away from each other.

As in the preceding case, the rods 4, 5 to be connected are fitted on either side of the clamp 6 one edge of each rod being inserted between the parts 6a and 6b of the clamp so that said rods are rigidly held by this member. Each rod engages the clamp so as to occupy about one half of its height, the two rods thus engaged contacting each other with their adjacent ends as shown in FIG- URE 5.

Under these conditions, the face 6b of the clamp engages the front faces of rods 4 and 5, but its width is so calculated that it cannot exceed the width of the rod 4 which is covered by the adjacent rod 4 (see FIGURE 5), whereby this face 6!) is not visible by the spectator.

This clamp is advantageous in comparison with the sheath in that it avoids any projections or unevennesses 0n the screen face, whereby the diffusing element presents a continuous surface from top to bottom of the panel.

In order not to impair the rigidity of the panel in spite of the rod structure comprising interconnected superposed elements, the joints 7 thus formed between any two adjacent rods are shifted vertically from each other as shown in FIGURE 6.

Another improvement consists in rounding the ends of the rods constittuing the elementary screens.

FIGURE 7 shows in cross-section one portion of a screen made of trough-shaped rods 8 having rounded edges 9. It will be seen that in this case not only the lightreceiving portion 8a of the front face 8a of the rod but also the edge 9, which has been bent to provide a round edge, receive and diffuse the light emitted by the projector. The rods 8 overlap partially each other so that only a portion 8a of their front faces receives the light from the projector, which is located in the theater. that is the part indicated by T in FIGURE 7. Of course, this projector (not shown) has its optical axis substantially perpendicular to the small surfaces 8a, in other words this optical axis is parallel to the direction indicated by F in FIGURE 7. This round edge may, like said front face 8a, be treated with a view to ensure a proper diffusion of the light. This specific form of embodiment of the rods is particularly advantageous for projecting pictures from projectors disposed outside the vertical median plane of the screen.

Of course, the invention should not be construed as being limited by the specific forms of embodiment shown and described herein, which are given by way of example only.

What I claim is:

1. A projection screen comprising a series of individual panels which are secured together in side-by-side relation, each panel being provided with a plurality of juxtaposed screen elements each having a light diffusing front face, said front faces together constituting a single curved projection surface and being substantially parallel to a direction perpendicular to the projection axis throughout the screen surface, each screen element comprising a plurality of superposed rods disposed end to end and connecting members for securing said rods one with the other.

2. A projection screen according to claim 1 wherein each rod has a trough-like configuration with a concave face and a convex face and each connecting member comprises a rigid sheath having a cylindrical cross-section and provided on its concave face with slideways in which the ends of two rods to be connected are inserted.

3. A projection screen according to claim 1, wherein each rod has a trough-like configuration with a concave face and a convex face and each connecting member comprises a clamp made from a resilient material and having a back face of substantially cylindrical configuration adapted to bear against the concave faces of the rods to be interconnected and a front face adapted to bear on that portion of the convex face of the rods which is covered by the adjacent rods.

4. A curved screen according to claim 1 wherein said rods are so distributed in the panel that their connecting joints are shifted in relation to one another.

5. A curved screen according to claim 1 wherein said rods are trough-shaped with their edges so bent that when they are positioned on the panels they provide alon their edges light-diffusing faces.

References Cited UNITED STATES PATENTS 1,882,829 10/1932 Hall 350-426 2,476,521 7/1949 Waller 350 FOREIGN PATENTS 524,931 4/1955 Italy. 1,283,342 12/1961 France.

JULIA E. COINER, Primary Examiner. 

